Radiant heat cloth drier



March 5, 1963 B. R. ANDREWS, JR., ET AL RADIANT HEAT CLOTH DRIER 4Sheets-Sheet 1 Filed March 11, 1960 v INVENTORS BERNHRD 1?. HNDREM SJKBY PAUL GOOD/P/Cf/ flTTOR/VEY Mam}! 1963 B. R. ANDREWS, JR., ETAL 3,07,703

RADIANT HEAT CLOTH DRIER Filed March 11, 1960 4 Sheets-Sheet 2 lid/JNVENTORS 3 BERNARD re. A4/0RAWI/k BY paw. @qa JR/w/ Arrow 5y March 5,1963 B. R. ANDREWS, JR, ETAL 3,079,703

RADIANT HEAT CLOTH DRIER Filed March 11. 1960 4 Sheets-Sheet 3 F/GB Z Wgw INVENTORS edwczn fli arrow/7 B. R. ANDREWS, JR., ETAL 3,079,703

Marqh 5, 1963 RADIANT HEAT CLOTH DRIER 4 Sheets-Sheet 4 Filed March 11,1960 IN V EN TORS 5 ERA 19190 R. FIVDREWJ'JQ By 9901. Game/cl) HT ram/5yilnited Filed Mar. 11, 1966, Ser. No. 14,458 9 Claims. (Cl. 34-457) Thisinvention relates to an apparatus for heat treating by radiant heatcloth or other material in web form, either for the purpose of drying itor for some other purpose.

One object of the invention is to provide a novel device of the abovetype in which the elements generating radiant heat are in the form ofhollow panels, preferably steel panels, and which are supplied withheated air from an air heating means by a novel system of forcedcirculation by which the heated air is circulated into and through thevarious panels and is then returned to the air heating means.

Another object of the invention is to provide an apparatus of this typewhich is so constructed that the heated panels can be quickly cooled byusing the same air circulating system that was used for heating thepanels.

Other objects of the invention will be apparent from the followingdescription of one embodiment thereof.

In the drawings:

FIG. 1 is a vertical section through a device embodying the inventiontaken on the line 1-1 of FIG. 2, with parts broken out;

FIG. 2 is a section taken in line 2-2 of FIG. 1; 1

FIG. 3 is a section taken on line 3-3 of FIG. 2;

FIG. 4 is a section taken on line 44 of FIG. 2.

FIG. 5 is a view of the driving means for the cloth supporting rolls.

The device herein illustrated includes a casing 1 which is divided by ahorizontal partition 2 to provide an upper heat-treating or dryingchamber 3 in which the cloth or which preferably has a valve 7 thereinby which the operation of the burner can be regulated.

The panels by which the radiant heat is generated are indicated at 8.Each has a flat shape and has an interior chamber 9, the opposite faces19 or each panel being flat and parallel to each other. These panels arearranged one above another in stack formation and with a space 11between each tWo adjacent panels. The manner in which the panels aresupported will be presently described.

Associated with the panels are two vertical row-s of cloth supportingrolls 12, said rows being indicated at A and B, and being placed on theopposite sides of the stack of panels. A roll 12 of row A is placedadjacent to and parallel with one edge of every other panel 8 of thestack, and one roll of the other row B is adjacent to and parallel withthe opposite edge of each of the other panels of the stack. Each rollhas a diameter somewhat greater than the thickness of each panel.

The cloth 2% to be dried or heat-treated is fed to the casing 1 throughan inlet opening 13 and passes underneath the bottom panel 8, to andaround the bottom roll 12 of the row B, and thence through the space 11between the bottom panel 8 and the second panel from the bottom, to andaround the bottom roll of the row A, thence back across the chamber 3through the space 11 between the second and third panels from thebottom-of the stack to and around the second roll 12 from the bottom ofrow B, and so on until the cloth has been laid around inc all the rolisof both of the rows A and B, as shown in FIG. 1. The cloth is deliveredfrom the chamber 3 through a delivery opening 14.

A supporting roll 12a for the cloth is shown just outside of and beneathboth the inlet opening 13 and the delivery opening 14. With thisarrangement there will be a straight stretch 15 of cloth located in eachspace 11 which is defined by each two adjacent panels, the top face ofeach straight stretch facing and situated closely adjacent to the bottomof the panel above it and the bottom face of each straight stretch 15facing and situated closely adjacent to the top of the panel below it.Each straight stretch or pass 15 of the cloth therefore has a panel bothabove and below it and is equally spaced from both panels, and eachpanel has a straight portion 15 or pass of cloth both above and belowit. While the rolls 12 may be mounted in any suitable way, yet in theconstruction shown each roll is provided at each end with an end portion59 that has a reduced diameter and these .end portions extend throughthe casing 1 and are supported in bearings 51 that are carried by asupporting frame 52 that is exterior to the casing.

Each panel 3 is heated to the proper temperature by delivering into itschamber 9 air which has been heated in the air heating chamber 4. Forthis purpose a fan 16, which is located in the air heating chamber 4,takes heated air from said chamber and delivers it into the bottom of avertically extending duct 17 which is located along the side edge of thestack of panels and which is provided with a series of openings or ports18, one of which communicates with the chamber'9 of each of the panels8. A second vertical duct 19 also extends along the side of the stack ofpanels and has a series of openings or ports 21, by which said duct alsohas'a communication with the chamber 9 of each of the panels 8. Thelower end of said duct 15 is open to the air heating chamber 4 as seenat 19a.

When the fan 16 is operating, therefore, it will take heated air fromthe chamber 4 and force it upwardly in the duct 17 and through theopenings 13 into the chambore '9 of the panels 8. Air in the chambers 9will be forced out of the panels into the duct 1) through the ports 21and this together with the reduced pressure in the chamber 4 due to thesuction created by the fan it; will produce a down draft in the duct 19,which will carry the heated air in the chamber 9 or the panels 8 backinto the air heating chamber 4, where it will be re-heated preparatoryto being again circulated through the panels 8.

There will, therefore, be established a continuous forced circulation ofheated air from the chamber 4 upwardly through the duct 17 and into andthrough the chambers 9 of the various panels 8, and from said chambersinto the duct 19 and back into the chamber 4. The straight stretches 15or" the cloth 2% that occupy spaces 11 between the panels 8 will each besubjected on both sides to radiant heat emanating-from the panels aboveand below it and will be dried in a still atmosphere which is relativelyfree from air currents. The moisture which is evaporated from the clothduring thedrying operation is withdrawn from the chamber 3 of the casing1 by 21 Sue tion pipe 69 which is connected to a suction'fan which isshown generally at 26 but without reference to any detail structure.During the drying or heat treating operation said fan may be operated ata low speed which is suiilcient to carry away the evaporated moisture asfast as it is released from the cloth.

The cloth 20 being dried or heat treated is fed through the chamber 3 bygiving rotary movement to the cloth supporting rolls 12 of one of thetwo vertical rows of purpose one of the reduced end portionsStl of eachroll 12' in the row of rolls indicated at B has fast thereon a sprocketwheel 43 which meshes with and is driven by a sprocket chain 44 that inturn is driven by a sprocket wheel 45 fast on a driving shaft 46, whichshaft may be driven from any suitable source of power (not shown).Inorder to maintain a proper driving engagementbetween the sprocketchain 44 and the sprocket wheels 43, there is provided a series ofseparate idler sprocket wheels 47 which engage the sprocket chain 44andare so mounted on'the frame 52 that each sprocket wheel 47 compelsthe,sprocket chain 49 to travel part way around each sprocket wheel 43as shown in FIG. 5.

There has been described above a forced air circulating system bywhichair is taken from the chamber 4 and forced upwardly in the ducts 17 andinto and through the chambers 9 of the panels 8 and from said chambersdownwardly through the ducts 19 back into the air heatingchamber 4. Afeature of theinvention is that this same forced air circulating systemcan also be used to cool r-apidly'the heated panels '8 if it isdesiredto do so as to prevent the cloth from becoming overheated orscorched. 1 e

This is accomplished by providing the upper end of each duct 19 with anextension 24 which passes through the top of thecasing ,1 and leads tothe inlet of a suction fan26.: Each extension'24 hastherein a balanceddischarge valve 25 which automaticallyremainsclosed as shown'in'FIG. 3during the normal operation of thedevice and while the cloth is beingheat treated or dried. Said suction fan can be operated by asuitablecontrol device .(not shown) to run either at a low speed or at ahighspeed. The balanced discharge valves 25 are each shown as comprisinga fiat valve member 30 which is pivoted to one side wall of thecorresponding extension 24 as shown at 28 so that said valve member canswing from a closed position resting on the valve seat 29 as shown infull lines FIG. 3 into an open position shown in dotted lines, therebyopening a direct communication between the upper end of each said duct19 and the suction fan 26. Each valve member 30 is weighted to hold itnormally in closed position by means of a weight 31 mounted on an'arm 32that is rigid with the valve member and extends upwardly therefrom at anangle thereto as shown in heavy lines in FIG. 3. The suction developedby'the fan 26 when it is being operated at low speed is sufficient towithdraw from the dryingchamber 3' the evaporated moisture as it isseparated from the cloth'during the drying operation, but isinsufiicient to "lift the weighted valves 30 so that said valveswill-remain closedwhile the cloth is being'dried or heat treated.

" When it is desired to cool the heated'panels, the burners 5 will beset'at low heat, and the suction fan 26 will be adjusted to run at high'speed. The high speed of said suction fan will develop an increasedsuction therein which is sufi'icient to overcome the closing tendency ofthe weights 31 on the valve members 30 and to hold said valves open asshown in dotted lines in'FIG. 3.

The opening of the valves 30 provides direct communi cation between theupper ends of the ducts 19 and the extensions 24, and since saidextensions are open to the 'suction inlet of the fan 26, the opening ofsaid valves provides a direct communication between said ducts and saidsuction inlet. Said ducts 19 also communicate with the chambers 9 of thepanels 8 throughthe openings-21. The lower end of each of'the ducts 17also communicates with the chamber 4 and the side wall of each duct 17has openings 18 leading into the chambers 9 of.the

various panels 8. Thus by increasing thespeed of the fan 26 to a pointat which the suction developed thereby is sufficient to open the valves30, there will be established 'a'current of cool air through theswinging valve 38 into 'the'chamb'er-4, up the-ducts 17 and through-thepanels 8 into the ducts 9 and; hence through the extensions 24 to thesuction inlet of the fan 26. The passage of this 4 cool air through thechambers 9 of the panels 8 will rapid. ly cool them to a point belowwhich the cloth would not be damaged even if it came into contact with apanel. When a cloth drying machine is used to dry cloth which has beenimpregnated with dye or finishing materials by circulating drying mediumover the web, there is a tendency for thin areas of the web to becomedry before the thicker portions with the result that the finishingmaterial or dye migrates from the still wetter areas to the drier areas.This results in an uneven color in the dried web. This phenomenon occursonly during the earlier stage of the drying cycle. We have found thatthe use of relatively low temperature radiant heat generating elementsand a longer exposure of the web to the radiant heat generated therebywill remove the water or solvent from the cloth during the early'dryingstage with little or no migrating movement of the finishing material ordye. As a result the finishing material or dye will be as evenlydistributed in the dried fabric as it was when the fabricleftthe'impregnating pan or coater. In the apparatus herein'shown theheating of the air in the chamber 4 may be so adjusted as to heat thepanels 8 to the temperature required .to prevent or reduce the migrationabovereferred to, and the manner in which the cloth is supported inthedrying chamber 3 provides the desired longer exposure of any portion ofthe cloth to the radiant heat generated by the panels 8.

We claim: I 1. An apparatus for heat treating material in web form,comprising an air heating chamber, a plurality of flat, hollow,radiant-heat generating panels arranged horizon tally one above anotherin stack formation with a space between each two adjacent panels, saidpanels being substantially rectangular in plan view with a width greaterthan the width of said web and imperforate over thearea of each panel toprovide a series of horizontal bafiles for inhibiting convection aircurrents, means to deliver heated air from the air heating chamber intothe interior of 'each panel thereby to heat the panel, and means to feeda length of web material through each said space successively, wherebyboth sides of. the web material in'each space will be subjected toradiant heat from the panels defining said space. a V a V i 2. Anapparatus for heat treating material in web form as defined in claim 1,and which includes a supply duct which has a separate communication withthe interior of each panel, a return duct whichhas a separatecommunication with the interior of each said panel and also withsaid airheating chamber and a fan associated with said supply duct to provideforced circulation of the air from the air heating chamber into andthrough the panels and through the return duct back into the air heatingchamber. 1 1

e 3-. A radiant-heat cloth drier comprising an; air heating chamber, aplurality of hollow, flat radiant heat generat- -ing panels situatedhorizontally one above another in stack formation and spaced verticallyfrom each other,

lfeed a length of cloth through the spaces between the panels of saidstack successively whereby the. cloth in each space is subjected on bothsides to the radiant heat generated by the two panels that define saidspace, a second vertically extending duct forming a second communicationbetween the interior of each panel and the, air heating chamber throughwhich the air in each panel is returned to the air heating chamber.

4. An apparatus for drying material in web form comprising, an airheating chamber, a plurality of flat, hollow, radiant-heat generatingpanels arranged horizontally one above another in stack formation with aspace between each two adjacent panels, said panels being substantiallyrectangular in plan view with a width greater than the width of said weband imperforate over the area of each panel to provide a series ofhorizontal bafiies for inhibiting convection air currents, means todeliver heated air from the air heating chamber into the interior ofeach said panel to heat said panel, means for feeding a length of webmaterial through each said space successively, means for continuouslyremoving the air from the interior of said panels and returning it tosaid air heating chamber, and means for continuously withdrawingmoisture released by said heat treating process.

5. Apparatus as defined in claim 4 further characterized by saidradiant-heat generating panels and said web feeding means beingcontained within a drying chamber, and a suction fan in communicationwith said drying chamber, said suction fan being operable to exhaustmoisture laden air from said chamber.

6. An apparatus for drying material in web form comprising an airheating chamber, a plurality of flat, hollow, radiant-heat generatingpanels arranged one above another in stack formation with a spacebetween each two adjacent panels, a vertical row of horizontal websupporting rolls on each of two opposite sides of said stack of panels,means supporting the rolls of the two rows of rolls so that the passesof the web from the rolls of one row to the rolls of the other row arelocated in the spaces between the panels, means to feed the web throughsaid spaces, a vertical supply duct at one side of the stack of panelswhich has communication at one end with the air heating chamber and alsohas communication with the interior chamber in each panel, a verticalreturn duct on the other side of said stack of panels communicating atone end with said air heating chamber, and also having communicationwith the interior chamber of each panel, means to establish forcedcirculation of the heated air from the air heating chamber through thesupply duct, into and through each panel and through the return ductback into the air heating chamber.

7. An apparatus for drying material in web form comprising an airheating chamber, a plurality of flat, hollow radiant-heat generatingpanels arranged horizontally one above another in stack formation with aspace between each two adjacent panels, a vertical supply duct providinga communication between the air heating chamber and the interior of eachpanel, a second vertical duct also providing a communication between theinterior of the panels and the air heating chamber, means to feed a webof the material to be treated through said spaces succes sively, meansto establish a forced circulation of air from the air heating chamberthrough the supply duct and into and through the panels and also throughthe second duct back into the air heating chamber, a suction fanequipped as usual with a suction inlet and capable of operating ateither a low speed or at a high speed, a duct extension providing acommunication between said second duct and the suction inlet of saidsuction fan, a balanced valve located in and normally closing said ductextension which valve is unaffected by the suction of the suction fanwhen it is operating at low speed but which will be opened by theincreased suction produced by said fan when it is operating at highspeed, thereby creating a strong updraft in said duct extension andsecond duct which draws the air in the panels into and through said fan,and means to reduce the generation of heat in the air heating chamberand to admit outside air thereto when the suction fan is operating athigh speed, whereby cool air will be delivered by the forced aircirculation through the panels, thereby cooling them.

8. In an apparatus for heat treating material in web form having an airheating chamber, a drying chamber having a plurality of flat hollowradiant-heat generating panels arranged horizontally one above anotherin stack formation with a space between each two adjacent panels, meansfor delivering heated air from the air heating chamber into the interiorof each said panel, means for exhausting air from the interior of eachsaid radiant-heat generating panel comprising a duct in communicationwith said panel and said air heating chamber and means for feeding alength of web material through each said space between said panelssuccessively; means for quickly introducing a supply of cool air intosaid apparatus for the purpose of terminating the heat treating process,comprising a duct extension formed on said duct for exhausting air fromsaid panels, said duct extension communicating with a suction inlet of asuction fan, said suction fan being operable at a high and a low speed,a balanced valve positioned in said duct extension normally closing saidduct extension and being adjusted to open said duct extension only whensaid suction fan is operated at said high speed, and valve means locatedin said air heating chamber for admitting a supply of cool air into saidchamber upon reduction of air pressure therein, whereby upon operationof said fan at high speed said balanced valve is opened and a flow ofair is created in said duct extension, associated duct for removing airfrom said panels and said air heating chamber causing a reduction in airpressure in said chamber whereupon said valve means therein open toadmit cool air thereby cooling said apparatus.

9. Apparatus as defined in claim 8 where said suction fan is providedwith a suction inlet in communication with said drying chamber wherebyupon operation of said fan at said low speed moisture laden air in saidchamber may be exhausted therefrom without opening said balanced valvein said duct extension.

References Cited in the file of this patent UNITED STATES PATENTS179,289 Field June 27, 1876 1,555,957 Ybarrondo Oct. 6, 1925 1,585,410Olofson May 18, 1926 2,397,091 Davis Mar. 26, 1946 2,772,486 JohansonDec. 4, 1956 2,956,523 Cady Oct. 18, 1960 FOREIGN PATENTS 1,945 GreatBritain AD. 1854

1. AN APPARATUS FOR HEAT TREATING MATERIAL IN WEB FORM, COMPRISING ANAIR HEATING CHAMBER, A PLURALITY OF FLAT, HOLLOW, RADIANT-HEATGENERATING PANELS ARRANGED HORIZONTALLY ONE ABOVE ANOTHER IN STACKFORMATION WITH A SPACE BETWEEN EACH TWO ADJACENT PANELS, SAID PANELSBEING SUBSTANTIALLY RECTANGULAR IN PLAN VIEW WITH A WIDTH GREATER THANTHE WIDTH OF SAID WEB AND IMPERFORATE OVER THE AREA OF EACH PANEL TOPROVIDE A SERIES OF HORIZONTAL BAFFLES FOR INHIBITING CONVECTION AIRCURRENTS, MEANS TO DELIVER HEATED AIR FROM THE AIR HEATING CHAMBER INTOTHE INTERIOR OF EACH PANEL THEREBY TO HEAT THE PANEL, AND MEANS TO FEEDA LENGTH OF WEB MATERIAL THROUGH EACH SAID SPACE SUCCESSIVELY, WHEREBYBOTH SIDES OF THE WEB MATERIAL IN EACH SPACE WILL BE SUBJECTED TORADIANT HEAT FROM THE PANELS DEFINING SAID SPACE.